The conventional fuel vehicle adopts an engine as the power output source, in order to keep the engine does not missfire the running speed of the engine must beyond an idle speed. When the vehicle is on the slope section, even if the driver does not step on the accelerator pedal, since the engine runs under a speed beyond the idle speed, the engine may also give a forward moment to ensure the vehicle will not slip backward. And most of the electric vehicles adopt a motor as the power output source, the output torque T of the motor may be calculated by the vehicle control unit according to equation T=T2×Gain where T2 is the maximum output torque of the motor under current vehicle speed value, and Gain is the accelerator-pedal travel value which is in the range of 0%˜100% and the value of Gain is proportional to the step depth of the accelerator pedal. The motor may drive the wheels with the calculated torque to ensure the vehicle reach the required speed. The motor itself does not need an idle speed to ensure the running of the vehicle, so when the driver does not step on the accelerator pedal, the motor has no output torque. However, when the electric vehicle is on a slope section, if the driver releases the accelerator pedal, since there has no output torque given by the motor, the vehicle may slip backward, thus may cause serious accidents, so it is desired to provide a method and apparatus in order to prevent the vehicle from slipping backward in uphill mode.